Since the initial advent of mechanized society, man has steadily been polluting his environment. Pollution takes different forms including water pollution, soil pollution, air pollution and the like. Moreover, such pollution exists at different levels in different areas of the country and of the world. In order to combat such pollution, it is desirable to know what various levels of pollution exist. It is also desirable to plot any large increases or decreases in pollution level.
In order to attempt to compile data on this subject, the Environmental Protection Agency (EPA) has recently proposed standards for different pollutant levels in different facets of the environment. The preferred embodiments of the present invention are specifically related to sampling the pollutant levels in municipal and industrial storm water discharges.
The pollutant level in municipal and industrial storm water discharges is a useful parameter in determining a plurality of different pollutant levels. First of all, this can determine the pollutant level in the air, as some of the pollutant level in the air will become dissolved in the rainwater that falls. In addition, there is a certain amount of silt which will also be collected. This silt will be somewhat representative of the pollutant level in and running off from the soil. In some cases it is desireable to sample a quantity of the first runoff water. In other cases it is desirable to sample the water which has already been flowing for a certain amount of time (for instance about 10 minutes) rather than merely sampling the first occurrence of water. This allows turbulence to mix all the silt and hydrocarbons into the water, in order to get a good sample. Once the sample is obtained using either technique, it is desirable to close off the sampling container such that further runoff water will not disturb the once-obtained sample. Therefore, the use of a mere bucket is clearly insufficient, as this would allow the sample, once taken to be circulated out. The sampling device must be able to accept water only after a certain running period and only a certain quantity. The prior art has never satisfactorily responded to this need.
For instance, two devices are known which have a function of sampling waste water and/or silt from storm drain runoff. One such device is made by the ISCO Company, P.0. Box 82531, Lincoln, NE 68501. ISCO model 2700 is a wastewater sampler which is electronically controlled to allow from 2 to 24 bottles to be filled during each sample. The interval between samples and the sampling amounts can be set as desired. Therefore, this is a high precision system. Unfortunately, this device is prohibitively expensive. Moreover, this system requires an electric source, either battery or AC electricity. This is highly disadvantageous in the field of the present invention, as the samples are typically taken at scattered locations in the field. It is inconvenient to have to change batteries in such a system, and even more inconvenient to have to run a source of AC electricity thereto. Therefore, this complicated system which is electrically operated is too expensive, too complicated and not portable enough for use in effectively collecting run-off and silt samples.
Moreover, this waste water sampler is suitable for use for sewage water only, and is not suitable for storm water or rainwater. The present invention is intended to be used in a plurality of different drain locations. The cost of the ISCO device would be it exorbitant if one of these devices were located in each drain.
Another known device is the LaMotte Chemical model IS.sub.3 integrated sediment stream sampler. This device is made by LaMotte Chemical Products Company, P.0. Box 329, Chestertown, MD 21630. This device only collects silt and does not collect water. Therefore, this device would be unsuitable for the functions of the present invention.
Various devices have also been known in the prior art which could conceivably be adapted to trapping liquid. Therefore, these devices could possibly be used in a field such as the present invention. For example, U.S. Pat. No. 3,826,144 to Wessels teaches an apparatus for sampling liquids. The device of FIGS. 3 and 4 of that patent shows a structure which could be used for sampling liquids to block off further liquid intake after the device is filled. However, this device has a number of disadvantages.
First, no structure in this device would enable the initial water to be discarded. The device simplistically operates using a float as a closure. Therefore, the initial period of operation of the Wessels device is much like the operation of a bucket--the initial water will be captured within the liquid collection area.
Moreover, the float of Wessels is actually larger in size than the diameter of the port through which the liquid enters. This makes the assembly of the structure very difficult.
Since Wessels does not teach or suggest any valve in addition to the structure, the float merely floats to the surface to seal off the entry way to the container. Therefore, a high volume of water could force its way into the collection container, circulating out water that was already therein. This is disadvantageous as discussed above.
U.S. Pat. No. 1,742,400 to Larsson defines a structure which uses a float to open and close a valve. However, the valve and float combination of Larsson has exactly the opposite effect to that desired to sample runoff water. Specifically, the valve of Larsson is normally closed when there is no liquid in the collection container. This valve opens when the liquid in the collection container rises. There is nothing in Larsson which would provide teaching to only open the valve after a certain amount of water was in the container, to allow water to stay in the container and to keep the valve closed thereafter.
U.S. Pat. No. 2,388,548 to Jurs uses a complicated sequence of weights, pulleys and arms in order to open and close a valve. In order to close the valve on the Jurs sampling device, the device must be subjected to an external force such as a jarring force. The field of storm water collection would not provide such a jarring force to initiate the sequence.
It is therefore an object of the present invention to define such a structure which can collect runoff storm water simply, reliably and cheaply.
In order to easily sample storm water at these remote locations, it is important that the liquid collection device include only mechanical structures, so that no external source of power such as external AC power lines or a battery is necessary. It is also important that the structure be made of cheap and readily available as well as durable materials. The inventor of the present invention has found that PVC piping is ideal for such a purpose.
According to the invention in its broadest conceptual structure, a liquid collection device is defined which stores a quantity of liquid. A cavity is defined within a first structure, this cavity having the purpose of storing the quantity of liquid. This first structure has an opening at one end through which the liquid is received, and is preferably formed of a length of PVC pipe which is capped at one end. A second structure is coupled to the open end of the first structure. This second structure blocks the opening of the first structure when the first structure stores more than a predetermined quantity of liquid. Therefore, the second structure performs the function of preventing any additional liquid from being accepted once the predetermined quantity of liquid is stored. Therefore, further liquid is prevented from being cycled out.
In a preferred embodiment of the invention, the second structure is a check valve. A third structure is disposed to receive a liquid stream and selectively allows water flow into the water storing area. According to one aspect of this invention, the water flow is stored only after preventing a predetermined amount of water flow.
A first embodiment of the invention is adapted to be located in a vertical position. This first embodiment includes a liquid intake portion open at one end, defining a reservoir for storing liquid therein. A valve means communicates with the reservoir and includes a spring-biased valve. This valve maintains liquid in the reservoir until more than a predetermined amount of liquid collects therein. At that time, the weight of the liquid forces the valve to open and allows the liquid to enter a liquid storage means. Structure is also provided for maintaining the valve in the closed position once the liquid storage means is filled, so that this initial water sample can be retrieved.
The valve may also be formed with a plurality of holes therein which allow liquid to leak out slowly. A second embodiment of the invention is adapted to have the liquid collection portion located in a horizontal direction. The liquid intake portion, however, faces in a vertical direction. Moreover, the opening of the liquid intake portion is a predetermined height above the collection portion This configuration prevents the initial water from entering the liquid collection portion. A check valve is provided in the liquid collection portion to maintain any water therein. Moreover, a closure valve is provided on the liquid intake portion which is biased into an open position, and is closed once the water level reaches a certain height. As in all the other embodiments, this embodiment is preferably formed of PVC piping.
In contrast, the device defined by the present invention can be built at the time of writing this application for one-hundredth the cost of the ISCO sampler and requires no electric source whatsoever, only using mechanical components.